Journal Articles

The number of journal papers and other articles in the medical literature published about ACDMPV is growing as awareness of the condition grows within the medical community. Below, in publication date order, is a list of articles we are aware of that have been published on ACDMPV. We attempt to provide the most comprehensive database of information on ACDMPV and appreciate any information concerning additional articles or other literature that becomes available.

“Nanoparticle delivery of FOXM1 or FOXF1 stimulates lung angiogenesis and alveolarization during recovery from neonatal hyperoxic injury. Delivery of proangiogenic transcription factors has promise as a therapy for BPD in preterm infants.” “The FOXF1 itself could be potentially used in ACDMPV (avoiding all potential questions about adverse effects of STAT3).”

Abstract: This is a case report of successful single-lobe lung transplantation for pulmonary hypertension secondary to alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV). A 6-year-old boy underwent living-donor single-lobe transplantation with the right lower lobe from his 31-year-old mother. Chest CT showed a mass rapidly growing in the native left upper lobe six months after transplantation, which was diagnosed as post-transplant lymphoproliferative disorder (PTLD) by a CT-guided biopsy. After immunosuppressant reduction and six courses of chemotherapy with rituximab, he underwent native left upper lobectomy for salvage lung resection 13 months after transplantation. Seven months after lobectomy, he has returned to normal school life without any sign of tumor recurrence.

Possible therapeutic approach (pending the development of a clinical trial): Cell transplantation of c-KIT-positive endothelial progenitor cells from donor lungs, to increase the development of pulmonary capillaries in ACDMPV babies

Possible therapeutic approach (pending the development of a clinical trial): Nanoparticle technology delivering a STAT3 protein to the lungs of babies, which could trigger the development of blood vessels in the lungs

Scientists used a gene editing method called CRISPR/Cas9 to generate mice that faithfully mimic a fatal respiratory disorder in newborn infants that turns their lips and skin blue. The new laboratory model allowed researchers to pinpoint the ailment’s cause and develop a potential and desperately needed nanoparticle-based treatment.

Mostly untreatable, Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACDMPV) usually strikes infants within a month of birth, according researchers at Cincinnati Children’s Hospital Medical Center, who publish findings in the American Journal of Respiratory and Critical Care Medicine. The disease starves the pulmonary system of oxygen after the lung’s blood vessels don’t form properly during organ development. The lack of tiny blood vessels called alveolar capillaries causes hypoxia, inflammation and death.

“There are no effective treatments other than a lung transplant, so the need for new therapeutics is urgent,” said Vlad Kalinichenko, MD, PhD, at the Cincinnati Children’s Perinatal Institute Center for Lung Regenerative Medicine and lead study investigator. “We identified a nanoparticle therapeutic strategy to increase the number of alveolar capillaries and help preserve respiratory function for at least a subset of the babies with this congenital lung disease.”

The disease has long been linked to mutations in the FOXF1 gene, an important regulator of embryonic lung development. The remaining mystery until this study is precise microbiological processes that fuel ACDMPV, according to the researchers.

Uncovering the STAT3 Connection

In collaboration with the team of Pawel Stankiewicz, MD, at the Baylor College of Medicine in Houston, the Kalinichenko lab analyzed genetic information from human ACDMPV cases to generate the first clinically relevant animal model of ACDMPV. They used CRISPR/Cas9 to recreate human FOXF1 mutations in the mouse. CRISPR-Cas9 allows precise gene editing by using an enzyme to cut out specific sections of a DNA sequence and reattaching the loose ends at a desired point to change a cell’s genetic makeup.

Having clinically accurate mouse models of disease ACDMPV allowed the scientists to overcome a longtime hurdle to understanding how the disease develops, authors write.

The work also relied on extensive bioinformatics analyses of clinical and laboratory data from biological tests. This includes a technique called ChIP-Seq (which analyzes protein-DNA interactions), and whole exome sequencing (which reveals the arrangement of all protein-coding regions of genes).

They also discovered that the S52F FOXF1 mutant protein did not interact with a protein called STAT3. The link is critical to stimulating the development of blood vessels in the neonatal lung. This led to a deficiency of STAT3 in developing lungs and improper formation of the pulmonary circulatory system.

Researchers also found STAT3 deficiency in donated samples from ACDMPV patients who had specific point mutations in the FOXF1 gene. The authors theorized that treating newborn mice with STAT3 would stimulate blood vessel development in the lungs, but they had to figure out how to get the protein to the lungs.

STAT3 Nanoparticle Solution

Researchers turned to nanoparticle technology to deliver a STAT3 mini-gene to lungs of newborn mice. They created a novel formulation for what are known as polyethylenimine (PEI) nanoparticles.

The gelatin-like PEI nanoparticles can carry therapeutic genetic material to different parts of the body by administering them to patients intravenously. Different formulations of PEI nanoparticles are currently being tested in clinical trials for adult cancer at other institutions, according to study authors.

Therapeutic administration of STAT3 DNA to newborn mice with the S52F FOXF1 mutation restored the ability of endothelial cells to form pulmonary blood vessels. This stimulated blood vessel growth in the animals and the formation of air sacs called alveolar.

“If the efficacy of PEI nanoparticles is confirmed in the clinical trials under way for adult cancer, PEI could be considered for STAT3 gene therapy in infants with ACDMPV,” Kalinichenko said. “Considering that ACDMPV is a rare disease, a multicenter clinical trial would be needed to assess the efficacy of STAT3 gene therapy in ACDMPV newborns and infants.”

The study’s first author is Arun Pradhan, PhD, a researcher who works in the Kalinichenko laboratory.

Funding support for the study came from the National Institutes of Health (HL84151, HL141174, HL123490, HL137203, HL132849 and grants from the National Organization for Rare Disorders.

The research team examined a series of pediatric lethal lung developmental disorders, including (1) ACDMPV, (2) acinar dysplasia (AcDys), (3) congenital alveolar dysplasia (CAD), and (4) other unspecified primary pulmonary hypoplasias. The team reviewed histopathological samples from lung biopsy or autopsy. The histopathological continuum in these lethal developmental disorders has made accurate diagnosis challenging. Over the past decade, genetic studies have revealed the causative role of the FOXF1 gene or other nearby variants in chromosome 16 for ACDMPV patients. In contrast, the molecular bases of two of the other lethal lung development disorders, AcDys and CAD, have remained poorly understood but the article discusses recent progress for these other disorders, including disruption of the TBX4-FGF10-FGFR2 pathway. The team proposes that for a more precise diagnosis of lethal lung developmental disorders such as AcDys and CAD, a diagnostic pathway including whole genome sequencing should be implemented.

This study reviewed clinical history, diagnostic studies, explant histology, genetic sequence results, and post-transplant course for 6 infants with atypical ACDMPV who underwent bilateral lung transplantation at St. Louis Children’s Hospital. Their histology was compared with infants with classic ACDMPV and the researchers also compared their outcomes with infants transplanted for other indications. Unlike in classic ACDMPV, histopathologic findings were not distributed uniformly and were not diffuse. Lung explants from infants with atypical ACDMPV demonstrated diagnostic but nonuniform histopathologic findings. Bilateral lung transplantation was performed at 4-20 months of age. Three transplanted children are alive at 5-16 years of age, similar to outcomes for infants transplanted for other indications. The 1- and 5-year survival rates for infants with atypical ACDMPV are similar to infants transplanted for other indications.

This review will familiarize the reader with the current indications for transplant and the referral and listing process. The current state of lung assist devices as a bridge to pediatric lung transplantation is discussed in addition to the technical aspects of the transplant procedure. Finally, posttransplant outcomes, including anticipated morbidity and the role of retransplantation, are clarified.

This paper from a team at Barcelona University, Spain focuses on imprinting in ACDMPV. We define paternal imprinting in the ACDA genetics guide as ‘the inactivation of a copy of a gene inherited from the father of an infant so that the gene is silent and not expressed. This leaves only the gene copy inherited from the infant’s mother active and expressed.’

We know that around 90% of mutations and 95% of deletions of FOXF1 are on the chromosome the infant inherited from his/her mother. It has thus been presumed that FOXF1 is subject to paternal imprinting (of course the majority of FOXF1 abnormalities arise de novo in the process of egg formation and are thus not actually inherited from the mother). However, there have been some findings that have been inconsistent with imprinting. Two prior cases of ACDMPV (both a familial case and a de novo case) have been described which were caused by FOXF1 mutations inherited from the infants’ fathers. Additionally 4 children have been identified who do not have ACDMPV but in whom both copies of chromosome 16 (in which FOXF1 is found) have been inherited from their fathers. If FOXF1 is subject to paternal imprinting this should have resulted in ACDMPV but this was not the case.

The authors of this paper thus investigate imprinting by studying 3 infants with ACDMPV, two identical twins and a separate infant. They found all 3 infants to have FOXF1 mutations that were derived from their mothers. However they then analysed the expression of FOXF1 in a variety of adult and foetal tissues and found that the genes derived from both mother and father were expressed in these tissues. They went on to study FOXF1 methylation. This is the process in which methyl groups are added to genes in order to switch them off. It is a key feature of imprinting. They found no methylation of FOXF1.

The authors conclude that the clinical and genetic data to date do not support the long-held view that FOXF1 is subject to paternal imprinting. They suggest an alternative, currently unknown mechanism is responsible for the maternal inheritance pattern of FOXF1 gene abnormalities. Thanks to Dr. Simon Ashwell, father to David, for this summary.

This is a case study in Italy of a 36-week pregnant woman that had second level prenatal testing after a routine ultrasound indicated possible heart and thorax issues. A prenatal echocardiography found no heart issues but an MRI identified small lung volume with decreased lung signal intensity. The family was counseled regarding a fatal prognosis. After birth, a chest X-ray showed bilateral pneumothorax with reduced and poorly ventilated lungs. An autopsy showed characteristics of ACDMPV; FOXF1 genetic testing was not performed. The authors believe prenatal testing measuring fluid lung volume (FLV) through MRI and Ultrasound, together with MRI lung signal intensity assessment, may help prenatally confirm or quantity the degree of lung underdevelopment. This summary prepared by Eliza Rista.

The genetic research team at Baylor College of Medicine in Houston, Texas, USA has worked in direct collaboration with a developmental biology research group at Cincinnati Children’s Hospital Medical Center in Cincinnati, Ohio, USA, including recently publishing together a mouse model of FOXF1 overexpression. The full manuscript entitled “Lethal lung hypoplasia and vascular defects in mice with conditional Foxf1 overexpression” as published in Biology Open can be found HERE. The paper was based off the PhD thesis of Avinash Dharmadhikari, a graduate student and mentee of Dr. Pawel Stankiewicz at Baylor and used mouse models to research what happens in mice when the FOXF1 gene is overexpressed. The research was a significant amount of work involving substantial experimentation with mice and follows up on prior work discussed in a 2014 paper. The 2014 study investigated the outcomes of FOXF1 duplication where four unrelated living people with duplication of FOXF1 were identified. Unexpectedly, none of the four patients had any lung abnormalities. However, Baylor was unable to measure the expression levels of FOXF1 in the 2014 study because the patients were otherwise healthy with regards to respiratory issues so no lung biopsies could be performed. As such, in the 2016 paper, Baylor implemented a mouse model study to increase the availability of samples in which to study FOXF1 expression levels. They developed a conditional model to switch on FOXF1 when they want in mice to change the expression levels and observed lung abnormalities when FOXF1 was overexpressed. Similar to FOXF1 loss, FOXF1 overexpression in mice is lethal. Based on the results of the 2016 mouse models, the research concluded that to be on the safe side, any future gene therapy would need to be careful with manipulating the expression of FOXF1 gene in humans because it could be problematic in humans if FOXF1 is overexpressed too much. This has important clinical implications when considering potential gene therapy approaches to treat disorders of FOXF1 abnormal dosage, such as ACDMPV.

ACDMPV was also mentioned in an article about research being conducted by the Cincinnati group referenced above (click HERE). The research is currently only applicable in mouse models and considerable further research is needed as to how the compound would apply to human lung diseases. From the article, “Researchers are developing a new drug to treat life-threatening lung damage and breathing problems in people with severe infections like pneumonia, those undergoing certain cancer treatments and premature infants with underdeveloped, injury prone lungs…Two laboratories at Cincinnati Children’s are developing a pharmacologic compound that in mouse models stimulates FOXF1 and promotes repair after lung injury.” The ACDA is hopeful for additional research that provides a full understanding of the molecular mechanism as to how the compound works and then further research into whether this could ever be applied to human patients at some point in the future.

The ACDA is grateful for the continued collaborative efforts between the research teams at Baylor and Cincinnati Children’s. This summary prepared by Eliza Rista.

This paper updates current knowledge about the genetics of ACDMPV based upon past research and new findings from recent work. Baylor College of Medicine in Houston, Texas, USA has accumulated the largest collection of ACDMPV samples worldwide (N=141 families), in which they have identified 86 pathogenic variants in the FOXF1 locus: 38 deletion CNVs, a complex rearrangement and 47 point mutations. DNA was not of sufficient quality for genetic testing in most of the remaining 55 families. The paper demonstrates the complexity of genomic and epigenetic regulation of the FOXF1 gene in 16q24.1. This summary prepared by Eliza Rista.

ACDMPV was part of the poster session for the 19th “International Conference on Prenatal Diagnosis and Therapy” in Washington, DC, USA on July 12-15, 2015. Vanderbilt University Medical Center prepared a poster based on an experience with a prenatal diagnosis of ACDMPV. A mother had a CVS due to concerns viewed on an ultrasound in the first trimester (cystic hygroma and echogenic bowel) and microarray analysis was done, which detected a deletion in the FOXF1 region. The family received counseling on ACDMPV and the baby was delivered at 39 weeks and unfortunately did not survive past the second day. This work is significant because according to the abstract, “This is the first reported prenatal diagnosis of ACDMPV devoid of a family history.” This summary prepared by Eliza Rista.

This is a review article, summarizing recent studies of FOXF1. It discusses where in the body the FOXF1 gene is expressed in humans and mice, the effects on mice who have the FOXF1 gene removed, the effects of duplication of FOXF1 and FOXF1 and cancer. Of relevance to ACDMPV parents, the authors point out that in ACDMPV-affected infants, 44 mutations involving FOXF1 and 36 deletions involving FOXF1 or upstream of FOXF1 have been reported thus far. In infants with ACDMPV for whom it was possible to determine from which parent a deletion arose, in all 24 they arose de novo on the maternal chromosome, consistent with the understanding the FOXF1 is paternally imprinted in human lungs. Thanks to Dr. Simon Ashwell, father to David, for this summary.

Mutations or deletions of the FOXF1 gene cause ACDMPV. The effects of, in effect the opposite, duplications of FOXF1 are unknown. This study investigated the outcomes of FOXF1 duplication. Four unrelated people with duplication of FOXF1 were identified. The first, a 4 1⁄2 year old boy has speech delay, behavioral issues and facial changes but he also has a further genetic abnormality that may account for these. The second, a 13 year old boy, has autism, behavioral problems and limited growth. He has two other genetic abnormalities that again may account for some of these issues. The third patient, an adult, has pyloric stenosis and other gut abnormalities. She has a daughter with similar gut abnormalities to whom she has passed the FOXF1 duplication. The fourth is a 10 1⁄2 year old boy with speech and motor delay and mild learning difficulties.

None of the four have any lung abnormalities. All four have duplications of FOXF1. The first three patients inherited the duplication from healthy fathers. This is consistent with the previous evidence that FOXF1 is paternally imprinted, i.e. the gene inherited from the father is inactive; only the gene inherited from a mother is expressed. However, the third patient inherited the FOXF1 duplication from a healthy father suggesting that FOXF1 is paternally imprinted in the lungs only, as she had gut abnormalities. In the fourth patient, the duplication arose de novo on the maternal chromosome.

The study shows that duplication of FOXF1 does not cause any lung abnormalities but can cause gut abnormalities. Thanks to Dr. Simon Ashwell, father to David, for this summary.

This research, performed by Professor Pawel Stankiewicz’s group at Baylor, investigated the issue of somatic mosaicism in the transmission of genetic diseases. Somatic mosaicism describes the situation where an individual has more than one type of genetic material in their body (eg both normal and abnormal copies of a gene). This arises due to mutations as our cells divide.

Conventional genetic tests often fail to find somatic mosaicism as it is often low-level (sometimes <1% of DNA) and thus cannot be detected. This has resulted in children with genetic diseases from parents with apparently normal DNA being labelled incorrectly as having a new ‘de novo’ genetic abnormality.

The researchers identified 100 parental couples who had had infants with apparently de novo mutations leading to a variety of genetic conditions. Families with ACDMPV were not included in the study but its results have some relevance to the ACDMPV community.

All families had been investigated with conventional genetic testing and neither parent had been found not the carry the genetic abnormality affecting their child. The researchers then developed novel detailed techniques to look more closely in the parents’ blood DNA in the specific area of genetic abnormality that were found in their child. Using these techniques 4 parents (4%), 2 mothers and 2 fathers, were found to have somatic mosaicism that was responsible for their child inheriting the condition. The parents’ amount of mosaicism (abnormal DNA) varied from less than 1% to 9% of total DNA.

The researchers developed a computer model to explore issues around recurrence risk. They calculated that, by virtue of having had a child with an apparently de novo genetic disorder, the risk of a couple having a second affected child is approximately 0.1% (one in a thousand). The risk was much higher in parents who were found to have mosaicism detected in blood DNA than those that did not. Parents of affected infants without detectable somatic mosaicism are likely to have mosaicism limited to eggs or sperm, but testing to confirm this is currently not possible. Mothers with mosaicism (as is always the route of transmission to an infant with ACDMPV) have a higher risk of recurrence than fathers as they tend to carry a higher proportion of affected eggs vs. sperm.

The take-home message for the ACDMPV community is that the risk for a couple of having a subsequent infant with ACDMPV might be able to be predicted by testing them for somatic mosaicism. Its absence would suggest a low chance of subsequent pregnancies being affected by ACDMPV. This might help in making decisions about pre-natal testing. Importantly this requires first the identification of a FOXF1 deletion in the affected infant. The lab is unable to test for somatic mosaicism in the parents of infants with ACDMPV who have a FOXF1 mutation due to unreliability of this test at such levels.

Professor Stankiewicz tells me that the Baylor lab routinely tests for low-level somatic mosaicism in parents of infants with ACDMPV who have FOXF1 deletions. So far none of 22 tested families have demonstrated mosaicism. Thanks to Dr. Simon Ashwell, father to David, for this summary.

This paper updates the publication by the same authors in 2009 in which they reported for the first time that abnormalities (mutations and deletions) in the FOXF1 gene and the area of chromosome 16 around the gene are responsible for ACDMPV. The 2009 paper found such abnormalities in 40% infants with ACDMPV. Since this publication, material has been collected from a further 47 infants. Thirty new de novo (see below) mutations in FOXF1 are described. This means that of the 93 infants with ACDMPV that Dr Sen’s group has studied 61% have been found to have a mutation in FOXF1 or a deletion around FOXF1. This confirms the role of abnormalities in the FOXF1 gene as the major cause of ACDMPV.

Two familial cases of ACDMPV are described. These confirm that FOXF1 is subject to paternal imprinting. This means that the FOXF1 gene inherited by an infant from his or her father is inactivated, but the gene inherited from the mother is active and expressed. Thus if an abnormality in FOXF1 develops in the production of an egg by a female (which occurs when she is in utero), this is expressed and will result in an infant with ACDMPV. However, if a similar abnormality occurs in the production of a sperm (by a mature man) the resulting infant will not have ACDMPV as FOXF1 is inactivated. However, the individual will be a carrier of the abnormality and can pass it on to his or her offspring. A female carrier can pass the abnormality to her children, which will result in ACDMPV.

The incidence of familial cases of ACDMPV in Dr. Sen’s combined series is approximately 2%. Dr. Sen mentions that his group is the only one in the world studying FOXF1 in relation to ACDMPV and that they operate a service to detect FOXF1 mutations and deletions pre- or post-natally on a research basis. Thanks to Dr. Simon Ashwell, father to David, for this summary.

This is a report of an infant with ACDMPV in which a novel genetic abnormality is described. The abnormality was detected by karyotyping. The infant was found to have a part of chromosome 16 inverted, close to the FOXF1 gene. The paper thus adds to the list of abnormalities of chromosome 16 that can cause ACDMPV. Thanks to Dr. Simon Ashwell, father to David, for this summary.

Introduction
It is now well known that genetic errors (deletions and mutations) within the FOXF1 gene are responsible for some cases of ACDMPV.

It has been predicted that the FOXF1 gene is subject to paternal imprinting. This means that the FOXF1 gene inherited from the father is partially inactivated and silent, leaving only the gene inherited from the mother active and expressed. Recent work has supported this prediction.

Methods
In this study blood was taken from 9 infants with ACDMPV who did not have mutations in the FOXF1 gene. A test called comparative genomic hybridisation (CGH) was performed at 16q24.1, the area of chromosome 16 in which FOXF1 is found. CGH can detect gains or losses in DNA.

Results
One of the 9 infants had a deletion of the entire FOXF1 gene. In the remaining 8 infants, deletions were found in the DNA distant and upstream from FOXF1. These deletions affected an area of the DNA that is involved in the regulation of the FOXF1 gene. None of these deletions were found in their parents blood and thus represent new (de novo) genetic errors. All of the deletions arose on the chromosome that the infant inherited from its mother. They thus represent abnormalities in chromosome replication when an egg is being made in a mother’s ovary. The study additionally showed that FOXF1 is not expressed equally from maternal and paternal DNA, further confirming paternal imprinting.

Discussion
This study adds to the body of ACDMPV research to date in agreeing that mutations in or around the FOXF1 gene are passed to the affected infant through the mother, whether this be though de novo changes or familial cases of ACDMPV. It also shows that deletions upstream from the FOXF1 gene are commonly detected using CGH in infants with ACDMPV who do not have a mutation of the FOXF1 gene itself, further stressing the importance of CGH in the genetic assessment of infants with ACDMPV. This can be particularly helpful for parents interested in pre-natal diagnosis of future pregnancies. Thanks to Dr. Simon Ashwell, father to David, for this summary.

Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins and Anterior Segment Dysgenesis of the Eye: A Report of a New Association and Review of the LiteratureMerchak A, Lueder G, White F, Cole F, Sessions F
Journal of Perinatology, 21 327-330

Alveolar Capillary Dysplasia with and without misalignment of pulmonary veins: an association of congenital abnormalitiesGarola RE, Thibeault DW
American Journal of Perinatology, February 1998 15(2) 103-107

Fetal hypertension and the development of increased pulmonary vascular smooth muscle: A possible mechanism for persistent pulmonary hypertension of the newborn infant
Daniel L. Levin, et. al
The Journal of Pediatrics 1978;92:2:265-269
Department of Pediatrics, The University of Texas Health Science Center at Dallas, Dallas, TX

The Effects of Maternal Hypoxia and Hyperoxia Upon the Neonatal Pulmonary Vasculature
Stanley J. Goldberg, et al.
Pediatrics 1971;48:528-533
University of Arizona, College of Medicine, Department of Pediatrics, Tucson, Arizona